JP2002364564A - Scroll fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll fluid machine equipped with a discharge valve capable of securing a high energy efficiency over a wide operating range, while it is possible to achieve a reduction of the discharge passage resistance, securing of the strength and reliability of a valve element receptacle part, optimization of the reexpansion space, and suppression of abnormal opening of the discharge valve. SOLUTION: A discharge port is arranged in a position intersecting a straight portion of the winding start part of a stationary scroll member, and the valve element receptacle part of the discharge valve in the stationary scroll member is formed tapered, and at the discharge port between the innermost circumferential compression chamber and the compression chamber pressure receiving part of the discharge valve, a gap as an auxiliary communication passage is provided so that the compression chamber pressure receiving part can receive the pressure change of a working fluid directly by its whole area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll fluid machine provided with a discharge valve for handling refrigerant, air and other compressible gas, and more particularly to a reduction in discharge flow path resistance and a reliable strength of a valve body receiving portion. The present invention relates to a scroll fluid machine which is suitable for realizing a proper re-expansion space and suppressing an abnormal opening of a discharge valve to secure high energy efficiency in a wide operating range.

[0002]

2. Description of the Related Art Scroll fluid machines are widely used in various fields as compressors for refrigeration and air conditioning equipment. Development and research are being actively conducted as a fluid machine having advantages such as high efficiency, high reliability, and low noise compared to other forms of compressor.

[0003] One configuration of a scroll fluid machine will be schematically described with reference to FIG. The basic elements of the compression mechanism are the fixed scroll 2, the orbiting scroll 3, and the frame 7, and the frame 7 is fixed in the closed container 1. The basic components of the fixed scroll 2 are a wrap 2a, an end plate 2b, a lap tooth bottom 2c, a lap tip 2d, and a discharge port 2e.
The basic components of the orbiting scroll 3 are a wrap 3a, an end plate 3b, a lap bottom 3c, and a lap tip 3d.

[0004] The basic elements of a drive unit for orbiting the orbiting scroll 3 are a stator 12 and a rotor 13 as electric motors.
The crankshaft 11, the Oldham ring 9, which is a main component of the rotation preventing mechanism of the orbiting scroll 3, the crankshaft support member 18 that rotatably engages the crankshaft 11 with the frame 7, and the orbiting scroll 3 For crankshaft 1
And an orbiting scroll support member 17 that movably and rotatably engages the one eccentric pin portion 11a in the thrust direction which is the rotation axis direction. The Oldham ring 9 is disposed in the space 8 formed by the frame 7 and the fixed scroll 2 together with the orbiting scroll 3, and one set of two orthogonal key portions formed on the Oldham ring 9 is
, The remaining set slides on the keyway formed on the opposite side of the orbiting scroll wrap 3a.

As an oil supply system, the lubricating oil 10 stored in the lower portion of the closed vessel 1 is passed through an oil supply pipe 14 connected to the crankshaft 11 and an oil supply hole provided in the crankshaft 11. It is supplied to the compression mechanism and the support members 17 and 18.

Here, the operation of the basic elements will be described. The rotor 13 is given a rotational force by a rotating magnetic field generated by the stator 12, and rotates with the crankshaft 11 fixed to the rotor 13. Orbiting scroll 3
Is rotatably and rotatably engaged with the eccentric pin portion 11a of the crankshaft.
The rotation motion of the orbiting scroll 3 is converted into a turning motion of the orbiting scroll 3 by a rotation preventing mechanism such as the Oldham ring 9. The volume of the compression chamber 4 formed by meshing the fixed scroll 2 and the orbiting scroll 3 decreases as the orbiting scroll 3 orbits. On the other hand, the pressure of the working fluid in the compression chamber 4 increases. A discharge valve 19 having a leaf spring shape is provided at the discharge port 2e.
Is opened when the pressure in the compression chamber 4 becomes higher than the pressure in the discharge space 16.

Next, a compression operation of the scroll fluid machine will be briefly described with reference to FIG. FIG. 8 is a sectional view of the compression chamber 4 formed by meshing the fixed scroll 2 and the orbiting scroll 3. The winding start portion of the fixed scroll 2 is formed by arcuating the winding start portions 2a1, 2a3 of the outer line and the inner line,
The orbiting scroll 3 is formed of a straight line portion 2a2 connecting these arcs.
1 and 3a3 are constituted by arcs and a straight line portion 3a2 connecting these arcs. The compression chambers 4a and 4b are compression chambers in a compression process, and their volumes are reduced by the orbiting scroll 3 orbiting.

In the compression operation, the working fluid is sucked into the compression chamber 4 via the suction port 5 and the suction space 15 as the orbiting scroll 3 orbits. The sucked working fluid passes through a compression process such as the compression chambers 4a and 4b, and is discharged from the discharge port 2
e, and when the pressure in the innermost compression chamber 4c becomes higher than the pressure in the discharge space 16 (see FIG. 7), the discharge valve 19 is opened, and passes through the discharge space 16 and the discharge pipe 6. Then, it is discharged out of the closed container 1.

During the compression operation, the linear portions 2a2 and 3a2 at the beginning of both scroll windings are almost in contact with each other, and
After the volume of the innermost compression chamber 4c is reduced to almost zero,
The outermost compression chambers 4a and 4b communicate with the discharge port 2e. When the fixed scroll 2 and the orbiting scroll 3 are engaged and orbited, the suction space 15-the compression chambers 4a and 4b
Meanwhile, it is necessary to ensure sufficient airtightness so that leakage of the working fluid does not occur as much as possible between the compression chambers 4a, 4b and the compression chamber 4c.

In a scroll fluid machine having a discharge valve, Japanese Patent Laid-Open Publication No. Sho 59-105988 discloses a technique for reducing the re-expansion space in which the working fluid in the innermost compression chamber cannot be completely discharged and returns to its original state. Is disclosed. In this publication, as shown in FIG. 8, both scroll wrap winding start portions are constituted by arcs 2a1, 2a3, 3a1, 3a3 and linear portions 2a2, 3a2, and the volume of the innermost peripheral compression chamber 4c is substantially reduced. After reaching zero, the next compression chamber and discharge port 2e
And a discharge valve 19 configured such that the volume of the discharge outside communicating with the innermost compression chamber 4c is negligibly small as shown in FIG.

The discharge valve 19 comprises a valve body 19a, a support spring 19
b and the support plate 19c. JP-A-59-58187 discloses that the inner and outer walls of both spiral windings are formed by an involute curve and the involute curve forming the outer wall is formed at an arbitrary opening angle with respect to the shape of the scroll wrap winding start. And the involute curve forming the inner wall is formed with an inflection point advanced by 180 ° from the expansion angle as a starting point, and the starting points of both walls are connected by at least two arcs and a line connecting the two arcs, thereby forming a spiral. A technique of forming a central body is disclosed.
In addition, Japanese Patent Application Laid-Open No. 7-77178 discloses a technique related to a scroll wrap winding start shape for reducing noise due to gas re-expansion.

[0012]

SUMMARY OF THE INVENTION FIG.
The discharge valve described in JP-A-9-105988 has some problems. One is that the valve body 19 at the discharge port 2e is
Since the thickness of the distal end portion of the joint portion 30 with “a” becomes very thin, there is a high possibility that the joint portion 30 becomes insufficient in strength.
Further, since the gap 31 between the fixed scroll wrap 2a and the valve body 19a is extremely small, the fluid pressure acting on the pressure receiving portion of the valve body 19a becomes uneven, and the flow direction of the fluid pushing up the valve body 19a is disturbed. Therefore, the discharge valve 19 may be abnormally opened.

As shown in FIG. 9, it is ideal to reduce the re-expansion space and reduce the loss by reducing the volume of the discharge outside communicating with the innermost compression chamber to a negligible amount. However, it is necessary to cope with the deterioration of the strength reliability of the valve body receiving portion and the abnormal opening of the valve body.

Further, if only the shape of both scroll winding start portions described in JP-A-59-58187 is considered,
It is not possible to achieve a scroll fluid machine that can achieve high energy efficiency over a wide operating range.

Originally, a positive displacement compressor such as a scroll compressor is over-compressed when operated at a pressure ratio smaller than the designed pressure ratio, and conversely under-compressed when operated at a large pressure ratio. Factors that reduce energy efficiency are inherent. It is common to use a discharge valve for under-compression and an over-compression valve for over-compression, but it is not always necessary to use both a discharge valve and an over-compression valve in a wide operating range. However, it cannot be said that energy efficiency is improved.

This is because, when two types of discharge valve and overcompression valve are installed at the same time, it is often impossible to provide a structure having a sufficient valve area due to the installation space. Even if it can be made, it is a valve structure such as a leaf spring type wrapper valve which increases the re-expansion space, and there is a possibility that the energy efficiency may be reduced. Therefore, a configuration has been considered in which overcompression is suppressed as much as possible by setting the design pressure ratio to be small, and the discharge valve responds only to undercompression. However, the problem is how much the design pressure ratio is reduced.

An object of the present invention is to solve the above-mentioned problems of the prior art and to reduce the discharge flow path resistance and improve the strength reliability of a valve body receiving portion in a scroll fluid machine having a discharge valve. It is an object of the present invention to provide a scroll fluid machine which secures a proper re-expansion space, suppresses abnormal opening of a discharge valve, and realizes a low pressure ratio.

[0018]

In order to achieve the above object, a scroll fluid machine according to the present invention is characterized by the features described in claims 1 to 5, and is particularly characterized by the following. The scroll fluid machine according to claim 1 as an independent claim, comprises a orbiting scroll member, a fixed scroll member, a compression chamber closed between the two scroll members to reduce the volume, and a compressed working fluid that is compressed by the compression chamber. A discharge port which is a communication passage for discharging from the discharge space to the discharge space,
A discharge valve provided at the discharge port which is opened when the pressure of the compression chamber is higher than the discharge space pressure; and a drive unit for orbiting the orbiting scroll member. The start portion is each a curved portion, and the connection of the curved portions is constituted by a substantially linear portion, the discharge port is disposed at a position intersecting the linear portion, and the valve element of the discharge valve provided at the discharge port A scroll fluid machine in which the receiving portion has a tapered shape, and the linear portions substantially contact each other during the compression operation to make the volume of the innermost compression chamber substantially zero, and then the next compression chamber communicates with the discharge port. In the above, the innermost peripheral compression chamber and the compression chamber of the valve body of the discharge valve are arranged such that the pressure receiving part of the compression chamber of the valve body of the discharge valve can directly receive the pressure change of the working fluid over the entire surface. On the discharge port side between the pressure receiving part It is characterized in that a gap as a co-communicating passage.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described.
This will be described in detail with reference to FIGS. First, the configuration of the scroll unit will be described with reference to FIG. FIG.
Shows the meshing state at the time of completion of ejection, and shows the same arrangement as that in FIG.

In this embodiment, the discharge port 102e is provided on the fixed scroll 102. Orbiting scroll wrap 10
The compression chamber formed inside 3a is connected to the extension side compression chamber 104b.
4. The compression chamber formed outside the orbiting scroll wrap 103a is referred to as an outer line side compression chamber 104a4. The compression chamber volume at the time of completion of suction is substantially the same on the inside line side and the outside line side.

Here, the shape of the winding start portion of the fixed scroll wrap 102a is such that the arcs of the outer winding start portion 102a1 and the inner winding start portion 102a3, and the linear portion 102 connecting these arcs.
a2. Similarly, the orbiting scroll wrap 103
The shape of the winding start portion a is defined by the arcs of the outer winding start portion 103a1 and the inner winding start portion 103a3, and the straight portion 1 connecting these.
03a2.

As shown in FIG. 1, at the time of meshing of the ejection completion, the winding start linear portions 102a2,
03a2 are almost in contact with each other and the innermost compression chamber is almost zero,
Further, one of the features of the present embodiment is that the discharge port 102e is disposed at a position intersecting the straight start portion 102a2 of the fixed scroll.

Next, the configuration of the discharge valve section will be described with reference to FIG. The discharge valve 119 is provided at the discharge port 102e. The discharge valve 119 includes a valve body 119a, a support spring 119
b, retainer 119c, guide 119d and working fluid
It is composed of an oil drain hole 119e.

This embodiment is characterized in that the valve body receiving portion 10 of the discharge port is provided.
2e1 is formed in a tapered shape, and the support portion 130 of the valve body 119a at the discharge port 102e is made thick as shown in the drawing, so that the compression chamber pressure receiving portion of the valve body 119a can directly receive the pressure change of the working fluid over the entire surface. As a result, the fixed scroll wrap 102a and the valve
That is, the gap 131 with the line a is secured. further,
The discharge valve is provided with a guide 119d that allows the valve body to move in the flow direction of the working fluid, and a drain hole 119e for the working fluid or oil that stops in the guide 119d.

The process from the completion of suction to the completion of discharge will be described with reference to FIG. FIG. 3 shows (a), (b), (c),
Changes in the compression stroke are illustrated in the order of (d). A series of compression operations is performed in the second cycle (d) after the suction is completed in (a).
Completes the ejection. When the suction is completed, the outer side compression chamber 104
a1 and the inner compression chamber 104b1 are configured as outermost compression chambers.
1 and 132b1 are respectively formed at two places.

The compression operation is performed in the order of (b), (c), and (d) in the order of
4a4, the inner compression chambers are 104b2, 104b3, 1
Proceed to 04b4. At the same time, 132a2,1
32a3, 132a4 and 132b2, 132b3, 13
2b4 and 2b4.

The side seal portions 132a4 and 132b4 are
Both scroll wrap windings are formed at the same portion where the linear portion is almost in close contact. When the state changes from (d) to (b), the outer compression chamber and the inner compression chamber become one innermost compression chamber 104c.
1 and at the same time, the innermost compression chamber 104c1 and the discharge port 1
02e starts communication. At this time, two side seal portions 132a1 and 132b1 are provided. The innermost compression chamber 104c1 is 104c in the order of (b) and (c).
The compression advances to 2,104c3, and the volume becomes almost zero in (d).

The discharge is started when the innermost peripheral compression chamber pressure becomes higher than the discharge space pressure and the discharge valve 119 is opened while the volume becomes almost zero through 104c1 to 104c3. In addition, 132a2, 132a
3, 132a4 and 132b2, 132b3, 132b4
And two locations each with different locations. This embodiment is characterized in that the outer / inner compression chambers 104a4, 104b4 start communicating with the discharge port 102e when forming the innermost compression chamber 104c1, and that the side seal portion is formed in the outer / inner compression chamber 104a4. In other words, there are always two locations for each 104b4.

The effect of this embodiment will be described. At the time of meshing of the discharge completion, the winding start straight portions 102a2 and 103a2 of each scroll wrap are almost in close contact with each other, the innermost compression chamber is almost zero, and the valve body receiving portion 102e1 of the discharge port is formed in a tapered shape. The expansion space can be reduced. At this time, the valve body 119a at the discharge port 102e
The thickness of the support portion 130 is increased to secure the strength reliability, and the gap 13 between the fixed scroll wrap 102a and the valve body 119a is increased.
Since 1 is secured, abnormal opening of the discharge valve 119 due to uneven fluid pressure acting on the discharge valve pressure receiving portion can also be suppressed.

Further, since the discharge valve 119 is provided with a guide 119d which enables the valve element 119a to move in the flow direction of the working fluid, it is possible to cope with a disturbance in the flow direction of the fluid pushing up the valve element 119a. Thus, a reliable opening and closing operation of the valve can be realized. Further, the provision of the holes 119e for draining the working fluid or oil that stays in the guide 119c allows the discharge valve to operate more reliably.

Further, by disposing the discharge port 102e at a position crossing the straight portion 102a2 at the start of the fixed scroll, the diameter of the discharge port 102e can be increased, and the discharge flow path resistance can be reduced. The outer and inner compression chambers 104a4 and 104b4 are the innermost compression chambers 104c.
By configuring to start communication with the discharge port 102e when configuring 1, the compression chamber related to the discharge operation can be limited to only the innermost compression chamber, and a reliable discharge operation can be performed.

Further, since the design pressure ratio is lowered and the side seals are always provided at two locations in the outer and inner compression chambers, the area of the center portion of the scroll wrap can be increased. It is possible to reduce the resistance of the discharge flow path, and the two side seals are provided, so that it is possible to sufficiently cope with leakage in the compression chamber. By the above effects, a scroll fluid machine including the discharge valve 119 suitable for securing high energy efficiency in a wide operation range can be realized.

A second embodiment of the present invention will be described in detail with reference to FIG. Except for the configuration of the discharge valve 219, it is the same as the first embodiment, and only different parts will be described.
The discharge valve 219 is provided at the discharge port 102e. Discharge valve 2
19 is a valve element 219a, a support spring 219b, a retainer 2
19c, guide 219d and working fluid / oil drain hole 219
e. The feature of this embodiment is that the structure of the guide 219c is different from the structure of the discharge valve 219 of the first embodiment, but the function is the same. By providing the guide pin portion on the valve body 219a side as in this embodiment, the valve body 219
There is an advantage that the weight of a can be reduced, and the natural frequency of the discharge valve 219 can be increased, so that the frequency response can be improved.

A third embodiment of the present invention will be described in detail with reference to FIG. Except for the configuration of the gap portion 231 between the fixed scroll wrap 102a and the valve element 119a, the configuration is the same as that of the first embodiment, and only different portions will be described. In the present embodiment, by forming the gap portion 231 in a tapered shape, turbulence at the time of discharge of the working fluid is reduced, and there is an effect of reducing flow path resistance and suppressing abnormal opening of the discharge valve. Since the gap 231 corresponds to the re-expansion space, it is better that the gap 231 is small. However, if the gap 231 is not so large relative to the stroke volume, the processing hole in the processing of the discharge port 102e can be used as it is, in addition to the above effects. It is also possible to reduce the processing cost.

A fourth embodiment of the present invention will be described in detail with reference to FIG. Other than the configuration of the scroll part, the first
The third embodiment is similar to the third embodiment, and only different parts will be described. FIG. 6 shows the meshing state when the ejection is completed. In the present embodiment, the ejection port 302e is
2 A compression chamber formed inside the orbiting scroll wrap 303a is called an extension side compression chamber 304b4, and a compression chamber formed outside the orbiting scroll wrap 303a is called an outside line side compression chamber 304a4.

In the outer / inner compression chambers, the volumes at the time of completion of suction are different, and the engagement positions at the completion of suction are also different. The outer compression chamber completes the suction at an angle of about 180 ° earlier and has a larger suction volume (hereinafter, referred to as asymmetric scroll wrap). The appearance when these suctions are completed is the first
This is different from the third to third embodiments. In this embodiment,
There is a case where the side seal portion is provided at two or more places in the outer line side compression chamber, and one of the features is that only the inner line side compression chamber is always provided at two places.

Since the number of seal portions does not decrease, it is possible to sufficiently cope with internal leakage of the compression chamber. As the scroll wrap is made asymmetric, the stroke volume can be increased with a compressor having the same diameter and the same height. Therefore, if the stroke volume is kept constant, the compressor can be downsized and the degree of freedom in design can be increased.
Further, since the torque fluctuation and the load fluctuation can be suppressed by the asymmetry, the mechanical loss can be reduced and the noise can be reduced.

[0038]

According to the present invention, reduction of discharge flow path resistance, securing of the strength reliability of the valve body receiving portion, optimization of the re-expansion space, and suppression of abnormal opening of the discharge valve realize high energy in a wide operating range. A scroll fluid machine provided with a discharge valve capable of ensuring efficiency can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a scroll unit according to a first embodiment.

FIG. 2 is a configuration diagram of a discharge valve section according to the first embodiment.

FIG. 3 is an explanatory view of a compression stroke of the first embodiment.

FIG. 4 shows a configuration diagram of a discharge valve section of a second embodiment.

FIG. 5 is a configuration diagram of a discharge valve section according to a third embodiment.

FIG. 6 is a diagram showing a configuration of a scroll unit according to a fourth embodiment.

FIG. 7 shows a longitudinal sectional view of a prior art scroll fluid machine.

FIG. 8 shows a configuration diagram of a scroll unit according to a conventional technique.

FIG. 9 shows a configuration diagram of a discharge valve section according to a conventional technique.

[Explanation of symbols]

 2, 102, 302 ... fixed scroll 2e, 102e, 302e ... discharge port 3, 103, 303 ... orbiting scroll 4, 104, 304 ... compression chamber 4a, 104a, 304a ... outside line side compression chamber 4b, 104b, 304 ... inside line side Compression chambers 4c, 104c: innermost compression chamber 7: frame 9: Oldham ring 15: suction space 16: discharge space 19, 119, 219: discharge valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mutsunori Matsunaga 390 Muramatsu, Shimizu-shi, Shizuoka Pref.Hitachi Air Conditioning System Shimizu Production Headquarters (72) Inventor Yu Otahara 390 Muramatsu, Shimizu-shi Shizuoka Pref.Hitachi Air-conditioning System Shimizu, Inc. Inside the Production Headquarters (72) Inventor Toshinori Anori 390 Muramatsu, Shimizu-shi, Shizuoka Pref.Hitachi Air Conditioning Systems Co., Ltd.Shimizu Production Headquarters (72) Inventor Isao Hayase 502 Kandachicho, Tsuchiura-shi, Ibaraki Pref. 72) Inventor Isamu Tsubono 502, Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratories, Hitachi, Ltd. (72) Inventor Masaki Koyama 502-Kartachi-cho, Tsuchiura-shi, Ibaraki Prefectural Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Kenichi Oshima 800 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Hitachi Tochigi Techno Co., Ltd. Gee in the F-term (reference) 3H029 AA02 AA14 AB03 BB42 BB44 CC03 CC05 CC06 CC15 CC25 3H039 AA03 AA04 AA12 BB05 BB28 CC02 CC03 CC07 CC08 CC29 CC30

Claims (5)

[Claims] An orbiting scroll member, a fixed scroll member, a compression chamber closed between the two scroll members to reduce the volume, and a communication line for discharging the compressed working fluid from the compression chamber to a discharge space. A discharge port that is a passage, a discharge valve provided at the discharge port that opens when the compression chamber pressure is greater than the discharge space pressure, and a driving unit that drives the orbiting scroll member to turn. The winding start portions of the outer line and the inner line of the member are each a curved portion, and the connection of the curved portions is constituted by a substantially linear portion, the discharge port is disposed at a position intersecting the linear portion, and provided at the discharge port. In addition, the valve body receiving portion of the discharge valve has a tapered shape, and during the compression operation, the linear portions substantially come into contact with each other so that the volume of the innermost compression chamber becomes substantially zero. Scroll fluid communicating with outlet In the machine, such that the compression chamber pressure receiving portion of the valve body of the discharge valve can directly receive the pressure change of the working fluid over the entire surface,
A scroll fluid machine, wherein a gap as an auxiliary communication passage is provided on the discharge port side between the innermost compression chamber and a compression chamber pressure receiving portion of a valve body of the discharge valve. 2. The scroll fluid machine according to claim 1, wherein a guide is provided on the discharge valve so as to move the valve body in a flow direction of the working fluid. 3. The scroll fluid machine according to claim 2, wherein a hole is provided for allowing a working fluid or lubricating oil staying in the guide to escape. 4. A suction-completed volume and a suction-completed time of an internal compression chamber formed on the inner side of the orbiting scroll member and an external compression chamber formed on the outer line side of the orbiting scroll member. 4. The side seal portions of the outer-side compression chamber and the inner-side compression chamber are each provided at two locations at any compression operation position of the orbiting scroll member. 5. A scroll fluid machine according to any one of the above. 5. The extension-side compression chamber has a larger volume at the time of completion of suction of the outer-side compression chamber than the extension-side compression chamber, and has a earlier completion time of suction, so that the extension-side compression chamber is in any compression operation position of the orbiting scroll member. The scroll fluid machine according to any one of claims 1 to 3, wherein two side seal portions are provided.